Micronuclei in exfoliated cervical cells as a prospective indicator tool for cellular genotoxic damage in high risk cancer patients, cytohistologic study versus DNA ploidy

ABSTRACT

The present study is an attempt to shed led light on clinical significance of micronucleus test as part of cytopathologic examination. One hundred females from the attendants of Cyto Diagnostic Unit of Early Cancer Detection in Obstetrics and Gynecology Hospital, Ain shams University, were chosen for the present study from cases presented with unhealthy cervix. They were diagnosed cytologically as 69 cases had inflammatory disease, 26 had cervical intraepithelial neoplasia and 5 cases had cervical cancer. One hundred females with healthy cervix were chosen as a control group. The present study showed that the mean age of the study group was 35.5 +/- 8.5 years compared to 33.6 +/- 7.8 years in the control group with no statistically significant difference [P > 0.05]. The difference between cases of CIN and cancer and controls were statistically significant [P < 0.05] as regard early age of marriage, parity and past history of cervical erosion as risk factors for the occurrence of cervical intraepithelial neoplasia. The frequency of micronuclei was [1.5 +/- 1.4] among study cases compared with [1.3 +/- 1.7] in the controls. The difference was statistically significant in low SIL and HSIL [2 +/- 1.2, 3.4 +/- 0.8 respectively] [P < 0.05]. The micronucleus test was found to be more sensitive test [92.3%] than cytological examination [61.5%]. DNA image analysis was found to be more specific [90.5%] than the micronucleus test [70.3%] and cytological examination [77.1%]. MN test compared with DNA cytometry was highly sensitive parameter for detection of genotoxic chromosomal damage caused by HPV with sensitivity of 100% while specificity was 74%. Cytological examination is still the most common screening test used in early diagnosis of CIN. DNA image and MN test are important tests for early diagnosis of genetic damage but still not easily to be used on big scale. MN test should be part of routine cytologic examination of high risk patients to diagnose synergistic action of carcinogens. As the DNA image and MN test are prospective parameters so, cases with positive cytology, for SIL even if the pathology was negative must do MN test and DNA cytometry. If the two proved to be abnormal, these cases should be considered highly risk group and should be put under strict follow-up including invasive procedures